I have the same problem with the german version, english version is ok.

Same problem, it is still not fixed. Especially frustrating bcs the english version has immense framerate drops like described in other posts. Literally unplayable, I wish i could get it refunded :c

The StarWolves.exe file corresponds to the English version, but it is possible to modify it with a hex editor:

Search for: 8B 4C 24 0C 57 8B 7C 24 0C 33 C0 85 FF 76 22 56 8B 74 24 0C 8A 14 30 32 D1 69 C9 0D 66 19 00 80 F2 04 <--
04 --> 8F

Search: E8 00 FF FF FF 8B 4C 24 4C 8B AC 24 88 00 00 00 D1 E9 81 F5 A2 6F 48 C5 <---
A2 6F 48 C5 --> E1 9A D5 5B

The mission texts will work

In principle, it also works with Russian executable files. Simply install it in Russian, then copy and place it in a directory you've created. Reinstall the game in the DE version.

Edit StarWolves.exe, which you've copied into the directory, and, as before, perform this operation.

8B 4C 24 0C 57 8B 7C 24 0C 33 C0 85 FF 76 22 56 8B 74 24 0C 8A 14 30 32 D1 69 C9 0D 66 19 00 80 F2 E6 <--
E6 --> 8F

and

88 00 00 00 D1 E9 81 F5 72 6D 62 A3 <--
72 6D 62 A3 --> E1 9A D5 5B

Copy the edited StarWolves.exe file back into the game directory.

Here's the executable for the DE version, based on the Russian version.

https://drive.google.com/file/d/1dDgQHpjtAlR5Hf4w-iA7niAR__EsAmoo/view?usp=sharing

Install the German version of the game,
After it, unzip and copy the StarWolve.exe it into the game directory.